Synopsis

This second of two daylighting tutorials on Radiance explains how to overlay analysis information on a rendered image.

Duration

You will need about 10 minutes to complete this tutorial.

Training and Accreditation

Successfully completing this tutorial fulfills one of the practical skills required for completing Level 3 of the Daylighting training module.

Resources Required

To complete this tutorial, first generate a rendered image in Radiance using the Final Render output option. If you are not sure how to do this, have a look at this tutorial here.

Tutorial

1. The final render produced by Radiance opens in the Square One Radiance Image Viewer, and in its raw state looks something like this :
   

   The raw Radiance rendered image.

While it may look just like any other computer rendered image, there is actually a wealth of data and information embedded in this image as a result of the Radiance rendering process. Let's see how we can access this information.

1. For instance, try clicking on various points within the image. At each point you click, the Radiance Image Viewer tells you the Lux level. To clear these values from the image, right-click on the image and select the Repaint Image option.
   

   Click to overlay Lux levels.

   

   Repaint Image to clear values.

   Radiance stores Lux levels at each point of the image.
2. Have a look at the toolbar situated just above the image window. The first tab is for the current, raw image. Click on the drop list under Information Overlay - these are the different information overlays that can be placed over the raw image.
   

   The Radiance Image Viewer toolbar.
3. Let's try some of these out. Select Contour Lines from the Information Overlay drop list. To generate this image overlay, click on the green Play button to the far right of the toolbar. A command prompt window appears briefly, and then the rendered image overlay appears in the image viewer.
   

   

   The command prompt window appears briefly followed by the contour lines image overlay.
   1. Note that there are now two tabs that appear in the top left hand corner of the image viewer. The second tab is for the contour line image, and the first for the raw rendered image. Click back on the first tab to return to the raw image.
      

      One tab appears for each image generated.
   2. Here are some other types of image overlays that can be generated by Radiance :
      

      Contour Bands.

      

      False Colour.

      

      Human Sensitivity.

      Some of the different types of image overlays possible with Radiance.
      1. If you wish to save any of the image overlays you have generated, just click on the required tab and then go to the File»Save Displayed Image As menu item.
         

         You can save any of the overlay images you have generated.

      And that's how you can use Ecotect and Radiance to perform a daylight analysis. For more information on the Radiance Image Viewer and its various settings and options, go here.